Method and device for producing preforms with special geometries

ABSTRACT

Preforms with a neck region and a preform body and having an enlarged geometry in comparison with the cavity of the injection mold are produced by injecting a polymer melt into the mold with a geometry of the cavity in the mold such that the radial extent of an inner space in the preform body thereby produced is not greater than the radial extent of the inner space in the neck region, the preforms are removed from the open mold by a removal gripper, and the preforms in the removal gripper are inflated using positive pressure such that the geometry of the inflated preform body is larger than the cavity in the injection mold.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of prior filed copending U.S.application Ser. No. 13/380,926, filed Mar. 16, 2012, the priority ofwhich is hereby claimed under 35 U.S.C. § 120 and which is the U.S.National Stage of International Application No. PCT/EP2010/058319, filedJun. 14, 2010, which designated the United States and has been publishedas International Publication No. WO 2010/149522 and which claims thepriority of German Patent Application, Serial No. 10 2009 030 762.1,filed Jun. 27, 2009, pursuant to 35 U.S.C. 119(a)-(d).

The contents of U.S. application Ser. No. 13/380,926, InternationalApplication No. PCT/EP2010/058319, and German Patent Application, SerialNo. 10 2009 030 762.1 are incorporated herein by reference in theirentireties as if fully set forth herein.

BACKGROUND OF THE INVENTION

The present invention relates to a method and a device for producingpreforms with a special geometry, which is enlarged in comparison withthe cavity in the injection mould.

In the production of plastic bottles, it is usual to firstly produce aso-called preform, which in a subsequent step is inflated into afinished plastic bottle by a blow moulding process.

In the preform production, conventionally, firstly a plastic material(e.g. plastic granulate) is melted and is introduced into the cavitiesof a closed injection mould. Such an injection mould generally has aplurality of identical cavities which are also designated asimpressions.

In order to form the preform geometry according to FIG. 1, theimpressions comprise in addition to a so-called neck region, a cavityrecess, into which a core projects. The core defines the inner space ofthe preform, the cavity recess together with the neck region the outercontour of the preform—together, they therefore establish the geometryof the preform.

After the injecting of the polymer melt into the multiple cavities, afirst cooling process is carried out, in order to achieve a sufficientrigidity for the preforms, which makes an opening of the injection mouldpossible. After the opening of the injection mould, the produced batchof preforms is conventionally removed from the mould with a removalgripper, wherein for this in known methods each preform is transferredinto an associated, mostly cooled removal sleeve of a removal gripper.

After the removal of the preforms from the injection mould, it is knownto transfer the preforms by means of a transfer gripper out from theremoval gripper into a further post-cooling device. After a sufficientcooling of the preforms in this post-cooling device, they are theneither conveyed directly to a blow moulding installation or are packedinto a carton for storage and transportation.

For a high degree of efficiency of the installation, it is important tokeep the cycle time as short as possible, in order to be able to produceas many preforms as possible. However, conflicting with a furthershortening of the cycle time is that fact that a considerable amount ofheat must be respectively dissipated from the preforms, in order tobring them effectively to an acceptable temperature level for packing.

This takes place on the one hand already in the injection mould itself,where a very aggressive cooling is provided both via the core and alsovia the cavity device. The removal sleeves of the removal gripper arealso generally (water) cooled.

In addition, under the brand name “Calitec” of the company Netstal, amethod has been introduced, in which the inner space of the preforms,which are situated in the removal gripper, are placed under pressure, sothat they position themselves with their outer wall intimately againstthe wall of the removal gripper and a particularly good cooling and alsoa recalibration is ensured. For this purpose, the transfer pins of thetransfer gripper have devices for sealing the inner space of thepreforms and for introducing a fluid, for example of air.

In the sequence described above, it is usual to generate a preform witha design, as is illustrated in FIG. 1. The type of design generallyresults from the fact that on the removal of the preforms from theinjection mould, on the one hand the core must be drawn out from theinner space of the preform, and on the other hand the preform itselfmust be removed from the cavity. These two procedures would not be ableto be directly and readily carried out in a preform geometry as isillustrated in FIG. 2. At least a core constructed in one piece couldgenerally not be drawn out from the inner space.

On the other hand, preform geometries as are shown in FIGS. 2, 3 and 8have some advantages, which will be explained further below.

SUMMARY OF THE INVENTION

For this reason, it is an object of the present invention to indicate amethod and a device by which preforms with a special geometry, e.g. anundercut—in particular in the shoulder region—or with a widening in thebase region can be produced, wherein the finished preform has a neckregion with a thread or a different closure device and a preform bodywith a larger or respectively widened preform body in comparison withthe cavity in the injection mould adjoins the neck region.

According to one aspect of the invention, the object is solved by amethod for producing preforms with a special geometry, wherein thefinished preform has a neck region with a thread or a closure device anda preform body, which adjoins the neck region and has an altered,enlarged geometry in comparison with the cavity of the injection mould,wherein preforms are produced by injecting a polymer melt into aninjection mould, in which the geometries of the impressions forming thecavity in the mould are designed in such a way that the radial extent ofthe inner space in the preform body thereby produced is not greater thanthe radial extent of the inner space in the neck region, the injectionmould is opened after a first cooling step, the preforms are removedfrom the open mould with a removal gripper, transfer pins of a transfergripper are introduced into the associated inner space of a preform andthe preforms are removed from the removal gripper by means of thetransfer gripper and are transferred into a post-cooling device, whereinthe preforms are either inflated in the removal gripper and/or in thepost-cooling device using positive pressure with respect to the cavitysituated in the injection mould and with the wall thereof are placedagainst the walls of an enlarged cavity in the removal gripper or thepost-cooling device.

According to another aspect of the invention, the object is solved by adevice for producing a preform geometry with an undercut, wherein thefinished preform has a neck region with a thread or a closure device anda preform body, which adjoins the neck region and has an altered,enlarged geometry in comparison with the cavity of the injection mould,wherein an injection mould is provided with a number of impressions forthe formation of preform geometries, wherein the individual impressiongeometries are configured in their cavity such that the radial extent ofthe free inner space in the preform body is not greater than the radialextent of the free inner space in the neck region, a plasticizing andinjecting device is provided, in order to melt a plastic material and tointroduce it into the cavity of the closed injection mould, a removalgripper is provided with a number of removal sleeves, which areconstructed respectively to receive preforms which are formed in theinjection mould, a transfer gripper is provided with a number oftransfer pins corresponding to the number of removal sleeves, which pinsare respectively able to be introduced into an associated preform, apost-cooling device is provided with a number of cavities, the transfergripper is constructed for transferring a batch of preforms from theremoval gripper to the post-cooling device and the transfer pins of thetransfer gripper have a sealing device for sealing a preform inner spaceand a fluid production device for the introduction of fluid into thepreform inner space, wherein the cavities of the removal sleeves of theremoval gripper and/or the cavities of the post-cooling device areenlarged radially and/or axially in comparison with the cavity realizedin the injection mould.

A central idea of the invention is to be seen in that the preforms whichare removed from the mould are firstly conditioned with regard totemperature in the removal device, i.e. are brought to a particulartemperature level, which on the one hand already significantly reducesthe risk of crystallization, but on the other hand makes possible afurther forming of the preform. In contrast to the systems hitherto, fora subsequent inflation process if applicable cooling is not carried outas intensively as possible, in order to obtain a preform which isalready hardened as far as possible.

Here, during the conditioning, the transfer pins can be inserted, inorder to seal off the inner space and place it under pressure, so thatan optimum contacting of the sleeve wall and hence conditioning andshaping is ensured.

According to a first aspect of the present invention, it is now alreadypossible to carry out an inflation process in the removal gripperitself, and in so doing for example to blow out the base of the preform,in particular in its axial extent. In this case, the cavity in theremoval sleeves of the removal gripper would have to be constructed in acorrespondingly enlarged manner in the base region. The radial outercircumference of the preform would thereby not alter substantially,which would also not be readily possible, because otherwise the preformcould not be reliably guided out from the injection mould. With thisprocedure, it is possible to form preform bases as are indicated forexample in WO 2008/041186 A2 and which are advantageous for thesubsequent stretch blow moulding. With a so-called “Capelio Design”,preforms can be formed with a thinner preform base, inter glia with theadvantage of a saving on material and a possibility for quicker cooling.This is of interest in particular when the production of such contoursby injection moulding has disadvantages.

After this conditioning, which can take place more quickly than thecooling hitherto, in particular when only or also in the post-coolingdevice an inflation process takes place, because then the preforms donot compulsorily have to be led to such a low temperature level, thepreforms are removed from the removal sleeve with the transfer gripperand are transferred into the post-cooling device. The cavities of thepost-cooling device (which can also be designated as a blow mouldingdevice) are enlarged here in comparison with the preform produced in theinjection mould such that in particular the radial extent of the innerspace is greater in the inflated preform than the radial extent of theinner space in the neck region of the preform. Of course, an axialwidening can also take place. Thereby, a widened shoulder region isproduced, which would constitute an undercut in an injection mould andcould not be readily demoulded.

By continuous or renewed sealing of the preform inner space with thetransfer gripper and corresponding application of pressure of thepreform inner space with a fluid (for example air), the preform whichwas previously conditioned with regard to temperature in the removalgripper is now inflated in the region of the preform body and placesitself against the wall of the injection moulding cavities of thepost-cooling device. This inflation is, however, only a “pre-inflation”in the sense of the finished plastic product which is subsequently to beproduced, and is therefore also designated hereinbelow as “preblowing”,because only an intermediate product for a finished plastic bottle or afinished plastic container is produced. For the production of a finishedplastic bottle or of a finished plastic container, a further blowmoulding step is required.

In the ways indicated above, preforms can be produced with an undercutgeometry, in which the diameter of the preform body is greater than itsneck region, its shoulder region therefore enlarges outwards, and/or isproduced with a Capello design. In so doing, either in the removalsleeve or in the post-cooling device or in both devices, a blow mouldingprocess can be carried out.

Such a preform offers a multitude of advantages. By the inflating of thepreform, the preform body as a whole enlarges, whereby in a subsequentblow moulding step more infrared light of a blow moulding machine can beabsorbed, with which the preform is heated up again for blow moulding.This leads to significant energy savings and lower investment costs inthe blow moulding machine or in operation. Furthermore, through theinflating of the preform, the wall thickness becomes smaller, as can beseen in FIGS. 1-3. The originally produced preform has a thicker wallthickness 1, whereas the preform geometries with undercut have thinnerwall thicknesses 2 and 3. Thereby, the preform can be brought morequickly and more accurately to the optimum stretch blow temperature thanis possible hitherto. Here also, an additional energy saving and lowerinvestment costs can be anticipated in the blow moulding machine. Inaddition, depending on the preform geometry, if applicable savings canbe made with regard to plastic material.

In addition, it is possible to provide the preform in the post-coolingdevice with a surface structure whereby the entire surface of thepreform is greatly enlarged on its outer side so that, in turn, moreenergy can be absorbed. This would further intensify the twoabove-mentioned effects. The surface structure would then become lostagain in the stretching process of the subsequent blow moulding.

However, the preform geometry offers not only advantages for thesubsequent blow moulding process; it also has advantages for its ownproduction process. Owing to the thinner wall of the preforms in thecooled blow moulding- or respectively post-cooling devices, the coolingtime as a whole can also be reduced here, which contributes to shortercycle times. This advantageously also leads to the fact that the risk ofcrystallization is distinctly reduced in comparison with preforms withthick wall thicknesses. Also, owing to the conditioning, instead of theintensive cooling hitherto, the dwell time in the removal gripper can bereduced.

The post-cooling device, acting as blow moulding device, shouldpreferably be water-cooled in this way. The more aggressive this coolingis, the better. Corresponding to the aggressivity of the cooling, thecycle time and also the risk of crystallization of the preforms isreduced.

In the removal gripper, on the other hand, the preform should preferablybe conditioned to a temperature which is favourable for a subsequentblow moulding process. Such a temperature range lies for example between90 and 150° C. This is of course only necessary when a subsequent blowmoulding process takes place. Without such a blow moulding process inthe post-cooling device, cooling can also be carried out veryaggressively again.

A significant shaping of the neck region of the preform is not intendedin any of these steps. In order to avoid such a shaping for exampleduring the sealing or positive pressure stage, the preform is preferablysupported from the exterior at least during the formation of thepositive pressure in the neck region or at least in parts of the neckregion. This support device can be constructed in the form of a jawdevice having two or more parts and being able to be opened and closed,arranged respectively in the region of each transfer pin of the transfergripper.

The jaw devices are preferably constructed so that they can be combinedand/or coupled with the post-cooling device, serving as blow mouldingdevice, such that, the inflated preform is supported completely into itsneck region during the inflation step. According to an advantageousembodiment of the invention, the jaw devices can likewise be cooled, inparticular water-cooled.

The conditioning is then further supported or respectively acceleratedin particular when also during the receiving of the preform in a removalsleeve its inner space is at least temporarily placed under pressure(even if no blow moulding takes place in the removal sleeve). Such apositive pressure can be kept in the range of 0.5-8 bar.

As the removal from the removal device or respectively the removalgripper can take place very quickly—and namely owing to the now pendingconditioning of the preforms to for example 120° and the greaterextending of the preforms with regard to dimensions, instead of thecooling hitherto—it can be necessary to provide two or more post-coolingdevices, into which the preforms can be transferred alternately from theremoval gripper. The post-cooling devices can also be configured so thatthey receive double, triple or a multiple of the batch of a preformbatch produced in the injection mould.

As a whole, with the device according to the invention preforms with anundercut can be produced in a quick cycle time, wherein this geometrysubsequently also has advantages in the further processing in a blowmoulding machine. Thus, multiple increases in efficiency are produced,both in the actual production process of the preform and also in thesubsequent processing step.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in further detail below and with reference tothe enclosed drawings. The drawings show in

FIG. 1 a cross-sectional view of a preform with a conventional geometry,as is produced with an injection mould,

FIG. 2 a cross-sectional view of a preform with a geometry withundercut,

FIG. 3 a cross-sectional view of a preform with a further geometry withundercut and altered base geometry,

FIG. 4 a sectional illustration of a preform received in a removalsleeve of a removal gripper with introduced transfer pin,

FIG. 5 a sectional illustration of a preform transferred into the cavityof a post-cooling device, not yet inflated, with introduced transferpin,

FIG. 6 a sectional illustration of a preform now inflated in thepost-cooling device, with undercut in the shoulder region,

FIG. 7 a diagrammatic illustration with sectional drawings of removal-and blow moulding device, by which the general mode of operation of thedevice is described, and

FIG. 8 a view of a preform with a Capello design in the base.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The procedure in the production of a preform with an undercut preformgeometry is to be explained with the aid of the drawings. Here,“undercut” means that a preform widens radially in the region of itsshoulder part, so that the undercut occurs with respect to the cavityshape of the injection mould.

Two such undercut geometries are illustrated in FIGS. 2 and 3, whereinFIG. 3 also shows an alteration to the base contour. Here, not only isthe external dimension or respectively the external diameter of thepreform in the preform body region greater than in the neck region, butin particular the radial diameter of the inner space diameter in thepreform body is greater than the radial inner space in the neck region.This geometry can not be readily produced in an injection mould. Atleast one core would have to be used, which could be contracted radiallyin the region of the preform body.

In order to nevertheless be able to produce a preform as shown in FIGS.2 and 3 with the conventional injection moulding technology, the preformis firstly produced in a conventional manner in an injection mould andafter the first cooling and the opening of the mould is removed in aconventional manner with a removal gripper. The removal gripper has aplurality of removal sleeves here, in which the preform is introducedmostly up to the neck region.

Both the injection moulding machines with injection mould and also theremoval devices are sufficiently known from the prior art.

In FIG. 4 only a single removal sleeve 12 of a plurality of removalsleeves of such a known removal device 10 is illustrated, in order to beable to show the holding of the preform 14 which was produced in theprevious step in the injection mould. The initially produced preform 14has a conventional shape with a relatively thick wall thickness and isalmost completely received in its body region in the sleeve, which (notillustrated in further detail here) is water-cooled. This cooling,whether by air or water, does not have to be entered into in furtherdetail here, because it is likewise known in diverse variant embodimentsfrom the prior art.

The front end of a transfer pin of a transfer gripper 16 is insertedinto the preform illustrated in FIG. 4, wherein the transfer gripper 16has a number of transfer pins 18 corresponding to the number of removalsleeves 12. At the front end of the transfer pin, an elastic sealingdevice is provided, which can alter (widen) in its radial dimension bycompression. In particular, a shaft (not illustrated) of the transferpin is pushed forward, in order to compress the elastic cuff and pressit radially outwards, whereby it deposits itself against the inner wallof the preform and one the one hand seals the inner space of the preformwith respect to the external environment, and on the other hand holdsit. This depositing takes place in particular in the region of the neckring, where a particular stability is provided.

In this example embodiment, from the front end of the transfer pin 18 astretching rod 24 extends into the dome-shaped, closed region of thepreform. Via this stretching rod 24 air can be supplied under pressureto the inner space of the preform. According to a particular embodiment,the stretching rod can also itself be constructed as a type of die andcan shape the base region of the preform by the application of adie-like pressure. Of course, both variants—die and air pressure—canalso be combined.

Through the build-up of a positive pressure in the range of 0.5-8 bar,the preform is pressed with its outer walls against the inner wall ofthe removal sleeve 12, acting as cooling sleeve, so that a particularlygood tempering and recalibrating takes place.

If the cavity of the removal gripper is configured accordingly, in thisposition the base region can already be blown out, as long as in sodoing no undercuts occur and the preform is held in a secure contour.Thereby, inter alia, preform contours with a so-called Capello designcan be produced, as is illustrated in FIG. 8.

Moreover, on each transfer pin 18 of the transfer gripper 16 heretwo-part jaws 22 are arranged, wherein the two jaw elements can be movedradially apart and towards each other. The assembly and device necessaryfor the movement of the jaws is not illustrated in the figures. In FIG.4 the two jaw elements are moved radially outwards. When these jawelements are moved radially inwards, they surround the neck region ofthe preform (or at least parts thereof) in a form-fitting manner, as canbe further illustrated subsequently with the aid of FIG. 5.

The removal device 10 with the removal sleeves 12 therefore serves notonly for the removal of the preforms from the injection mould, but alsofor the preconditioning to a particular temperature, for example 120°.In this temperature range, the risk of crystallization is alreadysignificantly reduced, but a plasticity of the preform is stillmaintained, under which the preform can be shaped. As the conditioningtakes place to a temperature range of for example 120° C.—and not to alower temperature—, a shorter dwell time is possible in the removalgripper than hitherto, which as a whole can contribute to a shorteningof the cycle time. This preconditioning also constitutes a difference incomparison with the working- and process steps known hitherto of thebest possible cooling.

It is to be noted here that for the case of inflating the preforms onlyin the removal sleeves and not also later in the post-cooling device, aconventionally intensive cooling can take place completely in theremoval grippers, instead of a conditioning.

After reaching the conditioning temperature, the preform 14 is removedfrom the removal sleeve 12 by means of the transfer pin 18 and, asillustrated in FIG. 7, is introduced into a post-cooling device (coolingblock) 26 by swivelling. The status after the immediate introduction ofthe preform 14 into the cavity of the post-cooling device 26, serving asblow moulding device, is illustrated in FIG. 5. Here, the two jaws 22 ofthe respective jaw device of a transfer pin 18 are already closed, inorder to be able to receive the forces of the blowing, and substantiallycompletely surround the neck region and the neck ring in the region inwhich no shaping is to take place. In the region in which the neckregion is surrounded by the jaws 22, the preform is supported from theexterior and can not alter in its dimension. Moreover, the jaw devicecan couple with the blow moulding device 26, so that except for theabove opening in the jaw device a completely closed-off cavity isproduced. The jaws are water-cooled here (not illustrated), in order tothus ensure as quick a removal of heat as possible from the preformregion with a thick wall thickness.

The preform, which is still warm and deformable, is now inflated byrenewed introduction of air with a corresponding air pressure of 0.5-8bar, so that the preform wall expands and places itself against theinner side of the post-cooling device constructed in a larger form. Theresult can be seen in FIG. 6, wherein it can be seen moreover that thepreform wall of the preform 28 has now considerably reduced.

As the post-cooling device is cooled in a correspondingly aggressivemanner (for example via water cooling—not illustrated), the preform 28can be brought very quickly to a temperature which is desired andacceptable for the subsequent packing, because now a very much thinnerwall thickness is present. After a sufficient cooling, the inflated andpre-blown preform 28 is removed from the post-cooling device, wherein itcan be seen in FIG. 6 that this removal is without problems in theshoulder region, because the jaws 22 cover the undercut and can beopened by the division into two. Owing to the smaller wall thickness,less risk of reheating of the preform 28 also exists after the removalfrom the cooled region.

After the opening of the jaw elements and the relaxing of the elasticgripping- and sealing device 20, the transfer pin 18 can be drawn outfrom the preform 28, wherein the preform 28 itself still remains in thepost-cooling device and is further cooled there. After a sufficientcooling process, the preform 28 can then be moved over a conveyor beltand, by a corresponding air impulse via air ducts which are notillustrated, can be ejected onto a conveyor belt.

As illustrated in FIG. 2, with a corresponding construction of thecavity walls, either in the removal sleeve or in the post-coolingdevice, structures can also be introduced into the outer surface of thepreform 2 on inflating.

As the pre-inflated preforms 28 are now greater in their dimension thanthe original preforms, the same number of preforms 28 as hitherto can nolonger be received in the post-cooling device which is constructed as ablowing device. For this reason, with a corresponding efficiency of themachine, it can be necessary to arrange two identical post-coolingdevices 26, for example above laterally to the machine, and to transferthe preform batches originating from the removal device alternately intoone or the other post-cooling device. This is illustrateddiagrammatically in FIG. 7, wherein only one removal sleeve 12 isillustrated, from which the preform batches are swivelled alternatelyinto the blow mould towards the right and into the only basicpost-cooling device toward the left (only indicated). In the respectiveposition, the transfer pin (then reference numbers 18′, 18″)—herewithout stretching pin—is then also swivelled. Of course, it is alsoadvantageous if each post-cooling device 26 can receive two or morebatches of preforms. For this, however, the arrangement of theimpressions must be coordinated accordingly both in the mould and alsoin the removal gripper and in the transfer gripper.

With the present invention, it is possible in a simple manner togenerate preforms with special geometries, for example with an undercutin the shoulder region or with a Capello design, which have severaladvantages both in their own production and also in the subsequentinflation process.

What is claimed is:
 1. A method for producing a preform, comprising:injecting a polymer melt into an injection mould having a cavity shapedto mold a preform formed with a neck region and defined by an innerspace having in a preform body region a radial extent which is notgreater than a radial extent of the inner space in the neck regionadjacent the preform body region; opening the injection mould after afirst cooling step; removing the preform from the open mould with aremoval gripper; and inflating the preform relative to the cavity of theinjection mould with use of a positive pressure so that the preformincreases relative to the cavity of the injection mould and a wall ofthe inflated preform is urged against a wall of a cavity of the removalgripper, said cavity of the removal gripper sized greater in a baseregion of the preform than the cavity of the injection mould, whereinsaid inflating step includes inflating the base region of the preform inthe removal gripper with the positive pressure in a range between 0.5and 8 bar.
 2. The method of claim 1, wherein a radial outercircumference of the preform is kept constant.
 3. The method of claim 1,further comprising tempering a removal sleeve of the removal gripper. 4.The method of claim 3, wherein the tempering in the removal gripperprovides conditioning of the preform.
 5. A method for producing apreform, comprising: injecting a polymer melt into an injection mouldhaving a cavity shaped to mold a preform formed with a neck region anddefined by an inner space having in a preform body region a radialextent which is not greater than a radial extent of the inner space inthe neck region adjacent the preform body region; opening the injectionmould after a first cooling step; removing the preform from the openmould with a removal gripper; inflating the preform relative to thecavity of the injection mould with use of a positive pressure so thatthe preform increases relative to the cavity of the injection mould anda wall of the inflated preform is urged against a wall of a cavity ofthe removal gripper, said cavity of the removal gripper sized greater ina base region of the preform than the cavity of the injection mould, andtempering a removal sleeve of the removal gripper to condition thepreform at a temperature range between 90° and 150° C.
 6. The method ofclaim 5, wherein said inflating step including inflating the base regionof the preform in the removal gripper with the positive pressure.
 7. Themethod of claim 6, wherein: the positive pressure is between 0.5 and 8bar.
 8. The method of claim 5, wherein the tempering step in the removalgripper provides cooling.
 9. The method of claim 1, further comprisingsupporting the neck region of the preform from outside, when applyingthe positive pressure during receiving of the preform in the removalgripper.
 10. The method of claim 9, further comprising placing a removalsleeve of the removal gripper immediately adjacent to the support of thepreform in the neck region to realize a complete circumferential supportof the preform.
 11. The method of claim 1, further comprising providinga post cooling of the preform after the inflating of the preform. 12.The method of claim 5, wherein a radial outer circumference of thepreform is kept constant.
 13. The method of claim 3, wherein thetempering step in the removal gripper provides cooling.
 14. The methodof claim 5, further comprising supporting the neck region of the preformfrom outside, when applying the positive pressure during receiving ofthe preform in the removal gripper.
 15. The method of claim 14, furthercomprising placing a removal sleeve of the removal gripper immediatelyadjacent to the support of the preform in the neck region to realize acomplete circumferential support of the preform.
 16. The method of claim5, further comprising providing a post cooling of the preform after theinflating of the preform.